Melancthon hanford



@einen taies germi @fitta IMPROVEMENT IN ROTARY ENGINES.

tittetlnmlr nimh tu in there trttn @Mettant uniting pitt tf tip. simu.

TO ALL WHOM IT-MAY CONCERN:

Be it known that I., MELANCTHON HANFORD, of Boston, in the countyofSuifolk, and State of Massachusetts, have invented an Improvement inRotary SteamV Engines; and do hereby declare theV following to be afull, clear, and exact description thereof, due reference being had tothe accompanying drawings, making part of this specification, andin'whichi Figures 1 and 2 are side views of the said-engine withcap-plate removed.

Figure 3 is a longitudinal and horizontal section, and

Figure 4 a transverse section of it: t 4 i I Figure 5 is a verticalsection ofl its induction and exhaust-chambers, and

`Figure 46 al representation of its two pistons.

The object of this invention, which is an improvement in that class ofsteam engines known as .rotary engines, or those in which two pistons,revolving in 'opposite directions and geared together, are employed, isto increase thelevcrage or power of the engine as a motor, by-increasingvthe length ofrsteani-bearing' and propelling surface ofthe pistons,thisbeing accomplished by making projections or arms upon the circumferenceof the pistons which mesh into notches or recesses formed in the other,the projections serving to partially rotate the pistons nwhen incontact, and to form a steam-bearing surface or leverage to aid inpropelling them, the two pistons being further connected together by aquadrangular series of sectional gears formed upon or making part of thecircumference vof the piston, as hereinafter explained.

By referring to the accompanying drawings illustrating my invention, thebox or casing of the engine is shown at A, having parallel cylindricalbores or chambers a a! intersecting each other and uniting to form onelargeV chamber, A; and4 further, having steam-induction andexhaust-chambers 6 c below the chambers a The revolving pistons areshown at B Bas yapplied within the chambers a a respectively, and seasto rotate in close proximity to opposite sides of the chambers, thepistons being supported by parallel shafts d al sustained by .the wallsof the casing-A. The pistons are circular in form, and havequadrangularly-arranged sectoral gears e e e e cut upon theirperipheries, the teeth of one piston meshing into those of the other,and each piston bein also formed with two roections fff and notches orrecesses on its o osite sides, and` g P J .9 .9 g .9 PP

approximating to a. semicircle in form, and between the sectoral gears ee e e, as represented in figs. 1 and 2 of the drawings. Thetwo pistonsare grooved longitudinally on opposite sides, for receivingsteam-packing plates heh,

a small chamber, z', being formed in each en`d of the piston and betweenthetwo plates, and having a lateral opening, j, to allow steam to enterVthe chambers z'eand force the plates against the interior faces ot thechambers a a', thus preserving a steam-tight joint between the faces ofthe pistons and their case. Additional chambers c Icare formedvertically in each end of the projections or teeth ffj" f of thelpistonsfor receiving packing-plates Z Z, secured therein in any suitablemanneijand supplied with springs to force them outward and in contactwith the inner periphery of the case A, by this means preserving asteam-tight joint about the ends of the pistons, in the same manner thatthe plates L 7L eiect their object, the steam being admittedv to contactwith the 'last-mentioned chambers k by a portl leading from the chambersit, before mentioned. vThe steam.. induction port leading into thepiston-chamber A is shown at 1n, and the eduction or exhaust-port atn,the

vport m leading from the steam-supply chamber b, and the port 'n openinginto the exhaust-chamber c, the chambers b and c being provided withsuitableinlet and outlet passages s t.

In the operation of the above-described engine, when used as a motivepower, and supposing the two pistons to be in thel position shown infig. 2 of the accompanying drawings, the steam entering theinduction-port m impinges against the tooth or'projection-f orf of thepiston B and rotates it inthe direction indicated by the arrow thereon,thesectoral gears eat this time meshing into `one of those o'f thepiston B and aiding in rotating the said piston B in an oppositedirection, or that indicated by itsarrow a, the rotation of this pistonbeing also aided by the pressure of the steam upon its tooth f and uponthe upper portion of its recessl g', the steam being prevented frompassing between-the pistons when inthis position by the teeth of. thegears e e, and when in the position shown in iig. 1, by thesteam-packing plates l Z operating upon the interior of the recesses gy.

Under the conjoint action above described the two pistons will berotated until the gears are out of engagement and one of the teethf ofthe piston B takes into the notch g of the piston B, the action oi' thetoothf' and notch g serving, in conjunction with the pressure of thesteam, to bring the two pistons into the position to allow the two nextadjacent gears e e to mesh into each other and complete, with the aid ofthe steam, a semirevolution ofthe two pistons on theiraxes, or into theposition shown in iig. 1 ofthe drawings, when the exhaust steam willpass through the port n and into the exhaust-chamber c, and from thenceinto the atmosphere.

The action of the packing-plates L h and l Z during the differentpositions of the pistons will readily manifest themselves to personsconversant with steam, as their construction and operation has beenbefore explained. The advantage gained in power by my construction andarrangement of the' pistons is dependenton the length of the teeth ff ofthe piston B, the excess of length ofthesc teeth beyond the periphery ofthe circular porv' tions of the pistons determining the extent of thegain. When lthe two pistons are in the position shown in iig. 1 theadvantage gained is not so great, as thel increase in power gained bythe action of the steam o'n the outer end of the piston A is to someextent lost in acting as a` motivepower upon the piston A', althoughtheL steam comes in at this point to act upon this piston and serve asan auxiliary to counteract this loss. But the full advantage of theincreased length of the piston, by means of its teeth ff, is gained whenthe positions ot' the pistons are changing from that shown'in fig. 6 tothat shown in fig. 1, as the periphery of the gears is equidistant fromtheir centres, while the toothj` of thepiston B, is projected beyond thecircumference of these gears, the increase in the leverage or power ofthe steam upon the tooth' increasing.very'rnpidly as it departs from thecircumference of the piston. By the arrangement ofthe recesses y y ofthe piston B room is made for ydisposing of the tcethff, while the teethact at the same time as motors to the said piston. By the mode of.connecting or gearing the two pistons together, as described, whilegaining other and important advantages, I dispense with gears outside ofthe case A, and apply the machinery to be driven by the engine directlyto the shaft of the said piston A.

I would remark that the above-described engine, although referred to inthe specification as a motor, may be employed to excellent advantage asa water-meter. A

In this case I have contemplated constructing the pistons of hard rubberin place of metal, andmake the slightly elastic properties of the rubberperform the 'oflice of packing the joints in place of the metallic barsbefore described.

I do not claim broadly the combination in rotary engines of cog-pistons,for I am aware that the same is. 'described and claimed.` in 'the patentof B. Holley, February 6, 1855;.but what I claim as my invention, anddesire to secure by Letters Patent, is f The herein-describedarranvement of thesmaller iston B and laroer iston B, rovided withro'ections e P e P P P J f, as and for the purposes set forth.

f MELANCTHON HA-NFORD.

Witnesses Fasucrs CURTIS, FREDERICK CURTIS.

